#!/bin/sh
#
# Copyright (C) 2000-2005 Erik Andersen <andersen@uclibc.org>
#
# Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
#

usage() {
	echo ""
	echo "usage: "`basename $0`" -k KERNEL_SOURCE_DIRECTORY -t TARGET_ARCH"
	echo ""
	echo "This utility scans the KERNEL_SOURCE_DIRECTORY directory and"
	echo "checks that it contains well formed kernel headers suitable"
	echo "for inclusion as the include/linux/ directory provided by"
	echo "uClibc."
	echo ""
	echo "If the specified kernel headers are present and already"
	echo "configured for the architecture specified by TARGET_ARCH,"
	echo "they will be used as-is."
	echo ""
	echo "If the specified kernel headers are missing entirely, this"
	echo "script will return an error."
	echo ""
	echo "If the specified kernel headers are present, but are either"
	echo "not yet configured or are configured for an architecture"
	echo "different than that specified by TARGET_ARCH, this script"
	echo "will attempt to 'fix' the kernel headers and make them"
	echo "suitable for use by uClibc.  This fixing process may fail."
	echo "It is therefore best to always provide kernel headers that"
	echo "are already configured for the selected architecture."
	echo ""
	echo "Most Linux distributions provide 'kernel-headers' packages"
	echo "that are suitable for use by uClibc."
	echo ""
	echo ""
	exit 1
}


#
# Parse our arguments
#
HAS_MMU="y"
while [ -n "$1" ]; do
	case $1 in
		-k ) shift; if [ -n "$1" ]; then KERNEL_SOURCE=$1; shift; else usage; fi; ;;
		-t ) shift; if [ -n "$1" ]; then TARGET_ARCH=$1; shift; else usage; fi; ;;
		-n ) shift; HAS_MMU="n"; ;;
		-* ) usage; ;;
		* ) usage; ;;
	esac
done


#
# Perform some sanity checks on our kernel sources
#
if [ ! -f "$KERNEL_SOURCE/Makefile" -a ! -f "$KERNEL_SOURCE/include/linux/version.h" ]; then
	echo ""
	echo ""
	echo "The file $KERNEL_SOURCE/Makefile or $KERNEL_SOURCE/include/linux/version.h is missing!"
	echo "Perhaps your kernel source is broken?"
	echo ""
	echo ""
	exit 1
fi
if [ ! -d "$KERNEL_SOURCE" ]; then
	echo ""
	echo ""
	echo "$KERNEL_SOURCE is not a directory"
	echo ""
	echo ""
	exit 1
fi


#
# Create a symlink to include/asm
#
rm -f include/asm*
if [ ! -d "$KERNEL_SOURCE/include/asm" ]; then
	echo ""
	echo ""
	echo "The symlink $KERNEL_SOURCE/include/asm is missing\!"
	echo "Perhaps you forgot to configure your kernel source?"
	echo "You really should configure your kernel source tree so I"
	echo "do not have to try and guess about this sort of thing."
	echo ""
	echo "Attempting to guess a usable value...."
	echo ""
	echo ""
	sleep 1

	if [ "$TARGET_ARCH" = "powerpc" ]; then
		set -x
		ln -fs $KERNEL_SOURCE/include/asm-ppc include/asm
		set +x
	elif [ "$TARGET_ARCH" = "mips" ]; then
		set -x
		ln -fs $KERNEL_SOURCE/include/asm-mips include/asm
		set +x
	elif [ "$TARGET_ARCH" = "arm" ]; then
		set -x
		ln -fs $KERNEL_SOURCE/include/asm-arm include/asm
		set +x
	if [ ! -L $KERNEL_SOURCE/include/asm-arm/proc ]; then
		if [ ! -L proc ]; then
			(
				cd include/asm
				ln -fs proc-armv proc
				ln -fs arch-ebsa285 arch
			)
		fi
	fi
	elif [ "$TARGET_ARCH" = "cris" ]; then
		set -x
		ln -fs $KERNEL_SOURCE/include/asm-cris include/asm
		set +x
	elif [ "$HAS_MMU" != "y" ]; then
		if [ -d $KERNEL_SOURCE/include/asm-${TARGET_ARCH}nommu ]; then
			set -x
			ln -fs $KERNEL_SOURCE/include/asm-${TARGET_ARCH}nommu include/asm
			set +x
		else
			set -x
			ln -fs $KERNEL_SOURCE/include/asm-$TARGET_ARCH include/asm
			set +x
		fi
	else
		set -x
		ln -fs $KERNEL_SOURCE/include/asm-$TARGET_ARCH include/asm
		set +x
	fi;
else
	# No guessing required.....
	for x in $KERNEL_SOURCE/include/asm* ; do
		ln -fs ${x} include/
	done
fi


#
# Annoyingly, 2.6.x kernel headers also need an include/asm-generic/ directory
#
if [ -e $KERNEL_SOURCE/include/asm-generic ]; then
	rm -f include/asm-generic
	ln -fs $KERNEL_SOURCE/include/asm-generic include/asm-generic
fi


#
# Create the include/linux symlink.
#
rm -f include/linux
ln -fs $KERNEL_SOURCE/include/linux include/linux